18101 research outputs found
Sort by
Aphanomyces spp. in Swedish crops and factors affecting their occurrence
Get PDFAphanomyces euteiches, A. cochlioides, and A. cladogamus are three devastating agricultural plant pathogens that respectively are causing diseases such as pea root rot, sugar beet root rot, and spinach root rot. This study aims to investigate the distribution of the three Aphanomyces species in parts of Sweden, Denmark, and Lithuania. It also aims to analyse macronutrient levels in the soil and explore potential connections between these soil factors and the pathogen presence. Methods of the study involve conducting biotests collected from the different regions and evaluate the presence of Aphanomyces spp. Additionally, a large data set from biotests conducted in commercial pea growing in Sweden was analysed.
The study revealed differences in the occurrence of Aphanomyces spp. between regions. Aphanomyces euteiches was the most widespread pathogen found in 31% of the tested samples and in 8 out of 13 totally tested regions. Aphanomyces cochlioides had a more limited distribution and was found in 14% of the investigated samples and in 4 out of 13 regions. Aphanomyces cladogamus displayed intermediate distribution in Sweden and was present in 12% of the tested samples, and in 5 out of 13 regions. Aphanomyces euteiches only affected pea plants. However, an overlapping host range was observed between A. cochlioides and A. cladogamus, which infected both sugar beet and spinach.
Furthermore, results showed significant differences in values of disease severity index between regions, pathogens, and for the interaction between region and pathogen. Soil analysis from all the soil samples showed that the calcium content (Ca-AL) ranged from 82 to 3600 mg/100g dry soil. When Ca-Al levels were above 250 mg/100 mg soil no species of Aphanomyces was detected, indicating disease suppressiveness. Similar results were observed from the commercial pea growing data set; no DSI values above 20 (with A. euteiches) was found in any soil sample with a Ca-AL value above 210 mg/100 g soil. Combined DSI data from regions was plotted against the combined data for soil properties and tested for correlations. Results from this analysis showed that high Ca-AL levels correlated significantly (P ≤ 0.043) with low DSI levels in both pea, spinach, and sugar beet.
Currently, pesticides against Aphanomyces spp. are very limited, highlighting the need to understand the distribution patterns and the relationship between macro nutrients and the pathogens for better disease management
Växtföljd i snittblomsodling
Get PDFAntalet snittblomsodlare har ökat signifikant i Sverige sedan 2014. Många av snittblomsodlarna arbetar enligt ekologiska riktlinjer, där jordhälsa är i stort fokus. För att bibehålla god jordhälsa är det viktigt att arbeta med växtföljd redan från början, då det är lättare att förebygga problem än att åtgärda dem. I en växtföljd ska många faktorer tas i beaktande, varvid jordburna skadegörare är en av dem. I denna litteraturstudie har de jordburna skadegörarna som angriper snittblomskulturer i svenska odlingar sammanställts och innefattar svampar, nematoder, bakterier, virus och insekter. Vissa av kulturerna som inkluderats i studien har fördelaktiga egenskaper, vilka presenteras som gröngödslingsgrödor.
Resultatet visar att många snittblomskulturer drabbas av samma skadegörare, vilket kan försvåra planeringen av en växtföljd. Resultatet visar även att flera av de helt eller delvis jordburna skadegörarna har en snävare värdväxtkrets och växtföljdsförslag för minskad uppförökning av dessa presenteras.
Denna studie ämnar öka kunskapen om växtföljd som växtskyddsinsats i snittblomsproduktion på friland och kan ses som ett hjälpmedel i planerandet av en hållbar växtföljd.The number of small-scale flower farmers have risen significantly in Sweden since 2014. Many of the farmers work in accordance with ecological guidelines, where soil health is a main focus. Using crop rotation from the beginning is important to maintain a healthy soil, as it is easier to prevent problems, than to remedy them later. There are many factors to consider when planning a crop rotation, of which soil-borne pests are one. This literary review has compiled the pests that are transmitted via soil and that affect cut flowers grown in Sweden and include fungi, nematodes, bacteria, viruses and insects. Some of the cultivars included in this review have beneficial properties, and in such cases are presented as cover crops.
The result of this review show that many of the cut flowers are affected by the same pests - a fact that may complicate the planning of a crop rotation. The results also show that many of the pests have a narrow range of host plants and suggestions for crop rotation to reduce proliferation of these pests are presented.
This review aims to increase the knowledge pertaining to crop rotation as a way of plant protection in field-grown cut flowers and can be seen as an aid in the planning of a sustainable crop rotation
Förskolegårdar i ett varmare klimat
Get PDFPå grund av klimatförändringarna och värmeböljor som följd har det drabbat städer hårdare på grund av att stadsutvecklingen präglas av förtätning och därmed är värmeöeffekten mer påtaglig. Detta ställer högre krav på att den urbana miljön kan hantera denna förändring för att ge människor en god livsmiljö. I detta arbete som grundar sig i fältstudier har vi valt att titta på hur barns utemiljö i förskola kan hantera framtidens värmeböljor för att minska risken att barns hälsa och välmående påverkas negativt.
Utifrån studiens resultat konstateras att man i planeringskedjan måste beakta flera aspekter som påverkar barns utemiljö i förskola och i ledet påverkar barns utveckling och hälsa. De aspekter som en varierad vegetation och val av markmaterial är viktiga att beakta då dess andel och egenskaper påverkar temperaturen och förskolegårdens klimat samt i längden den urbana värmeöeffekten. Genom fält- och fallstudier kan det konstateras att förbättringar kan göras på många olika sätt, så väl stora som små. Bristande är naturligt material, vegetation och förebyggandet av goda sol- och skuggförhållanden för att säkerställa en god utevistelse.Due to climate change and subsequent heatwaves, cities have been hit harder because of urban development characterized by densification, making the urban heat island effect more pronounced. This puts higher demands on the urban environment to cope with this change to provide people with a good living environment. In this study, based on field research, we have chosen to examine how the outdoor environment of preschools can manage future heatwaves to reduce the risk of negative impacts on children's health and well-being.
Based on the study's results, it is concluded that several aspects affecting the outdoor environment of preschools must be considered in the planning process, which in turn affects children's development and health. Aspects such as varied vegetation and choice of ground material are important to consider, as their proportion and characteristics influence the temperature and climate of the preschool yard, and ultimately the urban heat island effect. Through field and case studies, it can be noted that improvements can be made in many ways, both large and small. Deficiencies lie in natural materials, vegetation, and the provision of good sun and shade conditions to ensure a good outdoor experience
Blommande gräsmatta som alternativ till den traditionella
Get PDFI dagens urbana samhälle minskar den biologiska mångfalden på grund av förtätning. De urbana grönytorna utgörs till stor del av gräsmattor, och det finns tydliga normer kring hur dessa ska förvaltas för att uppnå dagens ideal. Denna hårda förvaltning påverkar genom flera aspekter den biologiska mångfalden och den ekologiska hållbarheten negativt. Arbetet syftar till att undersöka de för- och nackdelar den traditionella respektive blommande gräsmattan har, samt de normer och värderingar som influerar allmänhetens syn och användning av dessa grönytor i städerna. Detta för att visa hur den biologiska mångfalden och ekologiska hållbarheten skulle kunna öka i urbana miljöer och för att förstå vilka utmaningar och möjligheter som kan uppstå vid en omställning till blommande gräsmattor. Arbetet är avgränsat till den tempererade zonen samt artdiversiteten inom biologisk mångfald och metoden som används är en litteraturgenomgång.
Resultatet visar att den blommande gräsmattan bidrar till en högre biologisk mångfald då antalet växter är fler och blomningstiden är längre. Även fler pollinatörer och fler pollinerande arter besöker en blommande gräsmatta jämfört med den traditionella. Flera olika aspekter inom skötseln för den traditionella gräsmattan, så som klippning, bevattning, gödsling och bekämpning, påverkar den ekologiska hållbarheten negativt. Dessa skötselåtgärder krävs inte i lika stor utsträckning, eller överhuvudtaget, för en blommande gräsmatta. Det finns ett tydligt ideal om hur en gräsmatta ska se ut och skötas, och det finns en social press på att upprätthålla denna typ av gräsmattor. Trots de starka normerna och värderingarna ställer sig många positivt till en blommande gräsmatta på grund av estetiken och en ökad biologisk mångfald, men å andra sidan finns en konflikt i hur funktionen skulle påverkas. Den traditionella gräsmattan har en måttlig till hög tramptålighet och den blommande gräsmattan har en måttlig tramptålighet. För att underlätta vid en omställning till blommande gräsmattor föreslår vi att blommande arter skulle kunna sås in på redan etablerade gräsmattor och att kunskap skulle spridas till allmänheten genom informationsskyltar eller liknande. Slutligen anser vi att fördelarna för den blommande gräsmattan väger tyngre än nackdelarna och att den skulle kunna ersätta den traditionella gräsmattan för en ökad biologisk mångfald och ekologisk hållbarhet i urbana miljöer.In contemporary urban cities, biodiversity is experiencing a decline due to urban densification. Urban green spaces predominantly feature grass lawns, which are subject to distinct norms dictating their management to achieve today’s ideals. This extensive management does, by multiple aspects, affect the biodiversity and ecological sustainability negatively. This study aims to examine advantages and disadvantages of the traditional grass lawn respectively the flowering lawn, alongside the norms and values shaping public perception and utilization of these urban green spaces. This is done to display how biodiversity and ecological sustainability could be enhanced in urban environments and to comprehend the challenges and possibilities associated with a transition to flowering lawns. This study is limited to the temperate zone along with the diversity of species within biodiversity and the method used is a literature study.
The result indicates that flowering lawns contribute to a higher biodiversity due to increased plant diversity and prolonged flowering periods. Additionally, flowering lawns attract a higher number of pollinators and pollinating species compared to traditional grass lawns. Within the management of the traditional grass lawn there are aspects such as mowing, irrigation, fertilization and the use of pesticides that have a negative impact on ecological sustainability. These management measures are not needed to the same extent, if at all, in the flowering lawn. There is a clear ideal of what a grass lawn should look like and how it should be managed, and there is a social pressure to maintain this type of lawn. Despite these strong norms and values, there exists a notable receptivity toward flowering lawns owing to their aesthetic appeal and increased biodiversity. On the other hand, there exists a conflict regarding the change of function f the lawn. The traditional grass lawn has a moderate to high resistance to trampling and the flowering lawn has a moderate resistance to trampling. To facilitate a transition to flowering lawns, we propose to sow in the flowering species into already established grass lawns and that knowledge should be spread to the public through, for example, information signs. Finally, we contend that the advantages of the flowering lawn outweigh the disadvantages and that it could be a possible replacement for the traditional grass lawn to increase the biodiversity and ecological sustainability in urban environments
Gestaltningens roll vid översvämningar
Get PDFDagens klimatförändringar har ökat frekvensen av extrema väderhändelser vilket kräver proaktiv planering från kommuner och städer. Denna studie undersöker effekterna av översvämningar på tre bostadsgårdar i Uppsala och fokuserar på effekterna av regn och höga flöden. Genom att använda verktyget SCALGO och utföra platsbesök har vi bedömt dessa trädgårdars sårbarhet för översvämningar och därefter har bostadsgårdarna analyserats utifrån respektive gestaltning. Resultaten visar brister på de bostadsgårdar som analyserats när det gäller att mildra översvämningsrisker. Vi understryker behovet av innovativa och hållbara planeringsinsatser för att möta de utmaningar som översvämningar medför. Specifikt betonar vi den avgörande rollen som gröna infrastrukturer spelar i hanteringen av nederbörd och vikten av valet av växtlighet för att påverka vattenrörelser. Vi förespråkar långsiktiga planeringsstrategier som prioriterar integrationen av långlivad växtlighet, regnbäddar och minskningen av hårda ytor till förmån för genomsläppliga markmaterial för att förbättra infiltrationen av dagvatten. Sammanfattningsvis betonar denna studie betydelsen av att beakta klimatförändringarnas effekter i gestaltning. Genom att prioritera gröna infrastrukturer och göra strategiska växtval kan planerare effektivt mildra översvämningsrisker och bygga motståndskraftiga samhällen inför de växande klimatutmaningarna.Rapid climate change has heightened the frequency of extreme weather events necessitating proactive planning by municipalities and cities. This study investigates the impact of flooding on three residential gardens in Uppsala, focusing on the effects of rainfall and high flows. Employing the online tool SCALGO and conducting extensive site visits, we assessed the vulnerability of these gardens to flooding and analyzed the gardens design. The findings reveal shortcomings on the residential gardens that were analyzed, in mitigating flood risks. We underscore the need for innovative and sustainable planning approaches to address the challenges posed by climate change. Specifically, we highlight the pivotal role of green infrastructure in managing rainfall and emphasize the importance of vegetation selection in influencing water movement. We advocate for long-term planning strategies that prioritize the integration of long-living vegetation, rain beds and the reduction of hard surfaces in favor of permeable surfaces to enhance infiltration. In conclusion, this research underscores the critical importance of considering climate change impacts in design. By prioritizing green infrastructure and strategic vegetation selection, planners can effectively mitigate flood risks and build resilient communities in the face of evolving environmental challenges
Movement asymmetries in lame horses at the walk and their correlation to lameness in trot
Get PDFMost research concerning lameness examination methods are based on the gait trot. The walk has similar symmetrical qualities that could make it appropriate for lameness assessment. As some patients, and potentially some pathologies could benefit from being examined at the walk, the purpose of this case study was to investigate if movement asymmetry variables of the head/poll, withers and pelvis, showed statistically significant differences between horses when lame and non-lame after positive diagnostic anaesthesia. Forty-seven equine patients were included in the study, all incoming to the Swedish University Animal Hospital Horse Clinic (UDS Hästklinik) for lameness examinations during which a diagnostic anaesthesia was preformed and had a positive result (i.e. the lameness was blocked). They were measured using a multi-camera marker-based motion capture system at the walk and trot before and after local anaesthesia.
The displacement values of the markers placed on the horses were extracted from the motion capture software and analysed through a paired, two-tailed t-test to evaluate any statistical significance. The horses were grouped as to whether they were forelimb or hindlimb lame in trot and all lamenesses were converted into right limb lameness based on their values in trot. For both the forelimb and hindlimb lame horses, a smaller group of horses showing more severe lameness in trot were analysed separately again to be compared to the full group of forelimb/hindlimb lame horses.
Statistical significance was found for the difference in height of the minima of the poll (MinDiff Poll) in the “full group” and the difference in height of the maxima of the pelvis (MaxDiff Pelvis) in the “severe lameness group” for forelimb lameness. This study found no statistical significance before and after diagnostic analgesia for hindlimb lameness.
This may be due to the low sample size or a large variation of the compensatory motion patterns associated to lameness at the walk
Val av odlingssystem
Get PDFUnder mitten av 1900-talet genomgick lantbruket en revolution där avkastningen på diverse grödor fick en markant skördeökning. Men på senare tid visar det sig att dessa skördeökningar har börjat stagnera. De främsta orsakerna antas bero främst på klimatförändringar, men även försämring av markens kvalité som tär på markhälsan. Jordbruksmark brukas idag genom flera olika metoder och system både nationellt och globalt, vilket kan ge en effekt på markhälsan. Då lantbruket står inför stora utmaningar är det angeläget att undersöka och analysera hur markstruktur, växthusgasemissioner och avkastning påverkas vid val av odlingssystem som inkluderar bearbetningsmetod av jorden.
Fyra par gårdar i Skåne valdes ut i denna studie. De två gårdarna i respektive par ligger geografiskt nära varandra och förutsattes ha liknande väderlek och jordarter. På respektive pargård tillämpade den ena gården ett konventionellt bearbetningssystem med plöjning, medan den andra gården tillämpade ett alternativt bearbetningssystem med reducerad jordbearbetning eller genom principerna i det internationella konceptet Conservation Agriculture. För att studera hur odlingssystemen påverkar markstruktur, växthusgasemissioner och avkastning genomfördes både fält- och laboratoriestudier. Egenskaper som studerades var bedömning av markprofilen som växtplats med hjälp av mobilapplikationen ”Hur mår min jord?” samt mätningar av markvattenhalt, elektrisk konduktivitet, mullhalt, markens pH, vatteninfiltration, aggregatstabillitet, markstrukturstabillitet, växthusgasemissioner, dragkraftsbehov och avkastning. I studien användes höstvetets avkastning som en indikator för odlingssystemets produktionsförmåga.
Resultaten visade ingen signifikant skillnad mellan odlingssystemen oavsett egenskap som analyserades. Resultaten tydde på att t.ex. markstrukturen snarare påverkades av förutsättningar i marken som kan påverkas av lantbrukaren, där mullhalt och markens skrymdensitet hade större påverkan på markhälsan (mätt som aggregat- och markstrukturstabilitet), än valet av odlingssystem. Hur lantbrukaren hanterar sin jord, oberoende av odlingssystem, är avgörande för markhälsan. Att resultatet inte visade någon signifikant skillnad mellan odlingssystemen kan även ha berott på att gårdarna i studien har haft egen suveränitet i beslut för strategier och insatser under växtodlingsåret, där bland annat förfrukten och val av höstvetesort skiljde sig mellan gårdarna.
Studien visade att det är svårt att analysera och bedöma hur odlingssystem påverkar markstruktur, växthusgasemissioner och avkastning när gårdarna får ha egen suveränitet i beslut i sin växtodling. Studien visar att en viktig indikator för god markhälsa är en god markstruktur som man kan uppnå genom att bygga upp mullhalten i fält samt bibehålla en låg skrymdensitet. För att kunna analysera odlingssystemets effekt på avkastningen, bör samtliga upprepningar odla identisk grödsort samt ha identisk förfrukt. Det är dessutom viktigt att inkludera fler gårdspar dvs fler upprepningar för att kunna göra en mer säker statistisk bearbetning av resultaten. Framöver är det intressant att fortsätta utvärdera hur markhälsan påverkas vid val av odlingssystem.In the middle of 20th century, agriculture underwent a revolution where the grain yield of various crops increased a lot. But recently it appears that these yield increases have begun to stagnate. The main causes are said to be mainly due to the climate change, but also degradation of the soil quality, which decrease the soil health. Today, agricultural land is cultivated by using several different methods and systems both nationally and globally, which affect soil health in different ways. As agriculture faces major challenges, it is important to investigate and analyse how soil structure, greenhouse gas emissions and grain yield are affected by choosing cultivation system that includes tillage method of the soil.
Four pair of farms in Skåne in southern Sweden were selected in this study. The farms in each pair are geographically close to each other and were assumed to be exposed to similar weather conditions and have similar soil types. On each pair of farms, one farm applied a conventional cultivation system with mouldboard plough, while the other farm applied an alternative cultivation system with reduced tillage or by the principles of Conservation Agriculture. To study how the cultivation systems, affect soil structure, greenhouse gas emissions and grain yield, both field and laboratory studies were carried out. Characteristics that were studied were assessment of the soil profile using the application “How healthy is my soil?”, soil water content, electrical conductivity, soil organic matter, soil pH, water infiltration, aggregate stability, soil structure stability, greenhouse gas emissions, traction force and grain yield. In this study, winter wheat yield was chosen as an indicator of the production capacity of the cultivation system.
The results showed no significant difference between the cultivation systems regardless of the trait analysed. Instead, the results indicated that soil health was rather influenced by conditions in the soil that can be influenced by the farmer, where soil organic matter and soil bulk density had the greatest impact, than the choice of cultivation system. How the farmer managed his soil, regardless of cultivation system was crucial for soil health. The fact that the results did not show any significant difference between the cultivation systems regarding the factors tested in the study may had been due to the fact that the farms had their own sovereignty in decisions about strategies and efforts during the crop growing year. Where, among other things, the pre-crop and choice of winter wheat variety differed between the farms.
The study shows that it is difficult to analyse and assess how cultivation systems affect soil structure, greenhouse gas emissions and yield when the farms are allowed to have their own sovereignty in decisions in their crop production. The study shows that an important indicator for good soil health is a good soil structure that can be archived by improving the soil organic matter content in the field and maintaining a low soil bulk density. In order to be able to analyse the effect of cultivation systems on yield, all repetitions should cultivate an identical crop variety and have identical pre-crops. It is also important to include more farm pairs, i.e. more repetitions, in order to be able to perform a safer statistical processing of the results. Regardless, it is interesting to continue to evaluate how different cultivation systems affect soil health
Assessment of recreational values in peri-urban forests : a comparison of different recreational indices and their relationship with local users' opinions
Get PDFForesTRACE.jl: Raytracing Analysis for Utilising Lost Information in Laser Scanning Methods
Get PDFThe structure of a forest ecosystem is an important ecological, environmental, and socio-economic driver. Forest remote sensing is witnessing a rapid development of new technologies and methodologies for quantifying forest structure; however, they are not without flaws. Laser scanning, as one of the major data collection methods in RS, is negatively affected by both the scanned environment and the human error. This master’s thesis aims to address and quantify two of the established drawbacks of LiDAR scanning - occlusion, and user focus bias, to further help with LS optimalisation.
A new voxel-based raytracing package for the programming language Julia was developed to analyse occlusion, user focus bias and openness of point-clouds. It merges the start and endpoints of laser beams to construct laser rays, which traverse the voxel environment. In contrast to traditional point cloud analysis, which considers only the endpoints of the beams, introducing ambiguity into derived metrics and losing parts of the scanned information, our raytracing method provides a more comprehensive approach. The introduced raytracing method was demonstrated on the P-TLS platform. With the raytracing analysis performed on five demonstrational scans, we were able to illustrate the effect of user focus bias on occlusion and derived tree height. Additionally, we proposed a new method of measuring tree height using the openness quantifier – the G-T method. In our analysis, the traditional method of deriving tree height using a percentile of a quantile (P90 and P95) greatly underestimated the presumed height, as well as showed susceptibility to the user focus bias quantifier, unlike the more robust G-T method
Characterizing habitat preferences for common wild bee species in the Iberian Peninsula
Get PDFIn the last decades, studies have shown a global decrease in pollinators. This is of great concern given the essential role that bees play in pollinating numerous crops, which is crucial for human sustenance. Habitat loss emerges as the primary threat to bees across Europe. Within this context, the Iberian Peninsula stands out in importance for pollinator research. It is a bee hotspot, comprising more than half of Europe’s total bee species, but at the same time lacking basic ecological knowledge for many species. The problem is not a lack of data but rather the lack of digitization and compilation of existing datasets.
As for this, three years ago, researchers at CSIC, Spain, launched an initiative with the aim of combining available observations on bees across the peninsula and creating a large open-source database. Initial data retrieval and data cleaning were carried out in 2022 (Bartomeus et al. 2022). The subject of this bachelor’s work was to tap in on this work. The objectives were to: 1) incorporate more datasets into the database using a reproducible workflow, 2) clean and process the data, 3) combine it with EU data on CORINE land cover, 4) calculate habitat preferences for a selection of wild common bee species, and 5) examine if habitat preferences could be explained by a species phenological or latitude breadth, or by its sociality.
With this bachelor’s work, the database grew in size from 87,684 records to 93,803, with the incorporation of new datasets, containing bee observations from as far back as 1830 up until year 2022. Habitat preferences were calculated for the 61 most common wild bee species using null models based on the observation data.
The most preferred habitat was found to be agricultural land; arable land and pastures and dehesas, particularly, suggesting that agricultural land in the Iberian Peninsula can support biodiversity alongside crop production. Andrena spp. was shown to have high preferences on pastures and dehesas, highlighting this habitat importance. Natural habitats were also highly preferred, and urban environments were found to be the least preferred. Despite this, urban environments were shown to host some bee species. This wide variety of habitat preferences demonstrates the importance of maintaining high-quality landscapes with a variety of habitats to effectively support bee populations.
Correlation analyses indicated no significant relationships between habitat preferences and phenological or latitude breadth, or sociality, suggesting other traits such as floral preferences, nesting behavior, and abiotic conditions may influence habitat choice.
The large database on Iberian bees makes it possible to conduct all kinds of analyses. Future research can delve deeper into understanding the underlying traits driving habitat preferences of Iberian bee species or explore other aspects such as population trends over time